Rapid serial visual presentation (RSVP) measures the brain activity of a human subject while watching a stream of rapid images in order to find incongruities and inconsistencies in the images (i.e., “targets”). The RSVP protocol has recently been used as a powerful tool for high-throughput filtering of images into simple “target” and “non-target” categories as described by Thorpe et al. in “Speed of Processing in the Human Visual System” in Nature, vol. 381, pp. 520-522, 1996 (see the List of Incorporated Cited Literature References. Literature Reference No. 3). During a RSVP experiment, the images presented to the human subject are typically randomized.
Khosla et al. (see Literature Reference No. 1) identified that presentation order in RSVP sequences is important in determining brain computer interface (BCI) performance; however, no known works take target spacing in RSVP into consideration. Algorithms in previous systems assume that target chips are streamed to the operator infrequently. This has the disadvantage of potentially allowing targets to be presented at frequencies too high to elicit a detectable evoked response potential (ERP), such as the P300, in the operator.
Thus, a continuing need exists for a system that reduces periods of high frequency target presentation both for the case in which an estimate of the likelihood of target information given a specific image chip is present, and in the case in which such information is absent.